Just because he left the scene doesn't mean he's guilty. Personally, I would have left the scene as well. You don't know who else is in the vehicle, or if they have a gun. Granted, I wouldn't have driven home... that's just stupid. Drive a block or 2 and call the police on a cell phone, or drive to the nearest pay phone.
You know gun laws have gone too far when you no longer have the right to protect your life, liberty, and property. YOU are the first line of defense of your life, liberty, and property... police and laws are second to that. If every thief expected the home owner had a gun and expected they'd get shot during their crime, there'd be a lot less crime.
I heard of a case a couple years ago where a thief broke into somebody's home, grabbed a stack of electronics, and was on his way out when he was confronted by the homeowner with a pointed gun. The homeowner shot the thief in the leg, called 911, and the police and an ambulance carried him away. The thief was sentenced with some jail time.
In a just country, that'd be the end of the story. Well, the thief then filed a lawsuit against the homeowner that shot him in the leg. The thief won his case, and the homeowner was ordered to pay him half a million dollars. Moral of the story; if somebody breaks into your home, and you want to practice your right to defend your life, liberty, and property, you better unload your weapon in their chest.